Heretofore fibrous mat having a facing serving as a gas barrier, vapor barrier, reflective coating or the like has been cut into convenient lengths, stacked and packed under compression as batts or has been rolled under tension and compression and further compressed for packaging. A compromise combination of the advantages of the continuous length roll of insulating wool and the individual batt form of wool has been sought by attempts to perforate a continuous length of insulating mat transversely at regular intervals so that it can be separated manually in the field at the point of installation. This has been termed skip chop material.
Each of the forms of insulating strips of wool or mat have exhibited attributes and liabilities. The insulating properties of fibrous mat are a function of the thickness of the mat as installed. Shipping costs dictate minimizing the volume of the packaged product. An objective long sought in the art is to minimize the shipping volume of mat while maximizing its installed thickness and thus its recovery when released from compression in its package. The batt package exhibits the best recovery following a given degree of compression. This permits the greatest compaction and thus freight and warehousing savings is substantial. However, it presents problems in packaging since it is manually collected and stacked for compression. Labor cost for packaging is substantial. A wrong count of batts is sometimes placed in a package. When opened, a package of batts exhibit a resilience which tends to cause the batts to fly apart. The batts must be picked up individually for installation with resultant increased installation labor and cost.
The continuous length rolls exhibit poorer recovery and thus cannot be compacted to the degree to which batts for the same application are compacted. They therefore are more expensive to store and ship. Installation requires the roll to be cut into appropriate lengths in the field. Frequently, the rolls recover to vastly different degrees depending upon their position in the package since the leading roll when inserted into the package is subjected to less stress than the trailing roll against which the packer ram bears. INVENTION
The prior skip chopped insulation was packaged in rolls which were unsatisfactory from the standpoint of thickness recovery, tended to have damaged facings due to the stresses imposed in rolling and packing and could be separated only with difficulty and frequently with an uncontrolled tearing of the facing at other than the perforated regions. Attempts to weaken the perforations for enhanced separating characteristics resulted in greater frequency of accidental breaks in the facing and batt lengths during rolling, packaging and installing.